为什么一运行.,exe就停止工作啊？代码如下，求大神赐教

Question

#include
#include
using namespace std;
float x;
float fun(int n)
{
int i;
float P,t=1,a1,a2,Pn;
srand((unsigned)time(NULL));
for(i=0;i<=n;i++)
if(n=0)
t=1;
else
t=t*x;
a1=rand()%10;
P=a1*t;
a2=rand()%10;
Pn=x*fun(n-1)+a2;
return Pn;
}

void main()
{
int n;
float Sn;
cout<<"请输入n的值:";
cin>>n;
cout<<"请输入x的值:";
cin>>x;
Sn=fun(n);
cout<<Sn<<endl;
}

Answer 1

if(n=0)
->
if(n==0)